Question 1

Which of the following best describes Mendel's Law of Segregation?

Accepted Answer

Paired factors for a single character separate randomly so that half of the gametes receive one factor and half receive the other.

Question 2

A pea plant with genotype TtPp is crossed with another TtPp plant. What is the probability that an offspring will be tall and have purple flowers? (Assume T = tall, t = dwarf, P = purple, p = white)

Accepted Answer

$$\frac{9}{16}$$

Question 3

Which scenario best illustrates the law of independent assortment?

Accepted Answer

Alleles for seed color and seed shape are inherited independently in a dihybrid cross.

Question 4

In a monohybrid cross between two heterozygous pea plants (Tt x Tt), what is the expected genotypic ratio among the offspring?

Accepted Answer

1 TT : 2 Tt : 1 tt

Question 5

A couple, both heterozygous for a recessive genetic disorder (Aa), want to know the probability that their first three children will all have the disorder. What is the probability?

Accepted Answer

$$\left(\frac{1}{4}\$$right)^3$$ = \frac{1}{64}$$

Question 6

Which of the following is an example of incomplete dominance?

Accepted Answer

A cross between red and white snapdragons produces pink offspring.

Question 7

In codominance, how are the alleles expressed in the phenotype?

Accepted Answer

Both alleles are fully expressed, resulting in a phenotype that shows both traits.

Question 8

A pedigree shows a trait that skips generations and affects both males and females equally. What is the most likely mode of inheritance?

Accepted Answer

Autosomal recessive

Question 9

Which of the following best describes polygenic inheritance?

Accepted Answer

Multiple genes contribute to a single trait, resulting in continuous variation.

Question 10

If a man with genotype IAIB (blood type AB) has children with a woman with genotype ii (blood type O), what are the possible blood types of their children?

Accepted Answer

Type A and Type B only

Question 11

Which genetic phenomenon explains why Labrador retrievers can be yellow regardless of their genotype for black or brown fur color?

Accepted Answer

Epistasis

Question 12

A woman is heterozygous for sickle-cell anemia (Ss) and a man is also heterozygous (Ss). What is the probability that their child will be homozygous normal (SS)?

Accepted Answer

$$\frac{1}{4}$$

Question 13

Which of the following is NOT a feature of Mendelian inheritance?

Accepted Answer

Traits are blended together in offspring.

Question 14

In a dihybrid cross (AaBb x AaBb), what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

9:3:3:1

Question 15

A pedigree shows that every affected individual has an affected parent and the trait does not skip generations. What is the most likely mode of inheritance?

Accepted Answer

Autosomal dominant

Question 16

Which rule would you use to calculate the probability of two independent events both occurring?

Accepted Answer

Multiplication rule

Question 17

A couple, both carriers for cystic fibrosis (Cc), have two children. What is the probability that both children are unaffected?

Accepted Answer

$$\left(\frac{3}{4}\$$right)^2$$ = \frac{9}{16}$$

Question 18

Which of the following is a real-world example of a dominant genetic disorder?

Accepted Answer

Achondroplasia

Question 19

Which term describes an individual with two identical alleles for a gene?

Accepted Answer

Homozygous

Question 20

Which of the following best explains why sickle-cell disease persists in certain populations despite its negative health effects?

Accepted Answer

Heterozygote advantage provides resistance to malaria.

Mendel and the Genetics of Inheritance

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